The genetic code is the recipe for life, and provides the instructions for how to make proteins, generally using just 20 amino acids. But certain groups of microbes have an expanded genetic code, in ...

In a giant feat of genetic engineering, scientists have created bacteria that make proteins in a radically different way than all natural species do. By Carl Zimmer At the heart of all life is a code.

Despite awe-inspiring diversity, nearly every lifeform—from bacteria to blue whales—shares the same genetic code. How and when this code came about has been the subject of much scientific controversy.